Network route in Symbian

Hello.
In my application i need to use WLAN as a server and GPRS conection as a client. I opened 2 network sessions with different IAP - WLAN and GPRS.
Server side via WLAN works fine - QTcpServer accepts connection from my WiFi device but i can't connect via GPRS client (QTcpSocket) to some remote server. I get socket timeout error.
WLAN interface has IP:169.254.58.46
GPRS interface has IP: 172.28.163.149
Server has IP: 172.29.36.44

It seems that client doesn't find route path to remote server as they in different subnets.
How can i set default route address to Symbian route table or may be there is some other solution for my problem?

Hi, Leon.
Thank you for your answer.
I think this article is useful for me. It's a strange thing - i searched in forum for adding gateway to network but didn't find that article.
I solve my problem some other way: i use only one APN in each moment of time and start/stop other APN when it needs to send anything.
It may be worse solution so i consider to use your advice.